Signs and Symptoms of Domoic Acid Poisoning
" In humans, domoic acid appears to cause a non progressive acute neuronopathy involving anterior horn cells or a diffuse axonopath predominantly affecting motor axons. The acute neuronal hyperexcitation syndrome presumably results from the stimulus of central and possibly peripheral neurons, followed by chronic loss of function in neural systems susceptible to excitotoxic degeneration (i.e. hippocampus and anterior horn cells of spinal cord)." (1)
According to Lora E. Fleming of NIEHS Marine and Freshwater Biomedical Sciences Center (1), The acute symptom frequencies from Domoic Acid poisoning were the following: vomiting (76%), abdominal cramps (50%), diarrhea (4%), severe headache (43%), and loss of short-term memory (25%). Some patients also experienced acute headache, hyporeflexia, hemiparesis, ophthalmoplegia and abnormalities of arousal ranging from agitation to coma; seizures and myoclonus were observed acutely, especially around the face.
People usually contract the illness by eating shellfish contaminated with the Psudo-nitzchia diatom. Domioc Acid is a heat stabile protein, so even cooked marine foods pose a risk.
Gastrointestinal symptoms usually occur within the first 24 hours of eating the contaminated sea food, and neurologic symptoms may follow as long as 48 hours after ingestion.